Water purification system

ABSTRACT

The inventions relate to means for purifying water, primarily drinking water, and can be used in domestic water purification systems. The claimed filtered water storage unit for the storage device of a water purification system comprises a housing, an elastic chamber disposed therein for filtered water, and a region for pressurizing untreated water, which is defined between the wall of the chamber and the wall of the housing. The elastic chamber is made of a modified biaxially oriented thermoplastic elastomer and consists of a chamber body and neck, formed as a single piece, the neck being rigidly secured in the housing. The water purification system comprises a reverse osmosis membrane, a clean water discharge pipe, an overflow into a drain, a clean water tap, and a storage device comprising a filtered water storage unit and a hydro-automatic unit. In a first embodiment of a system with a storage device, the outlet of the controlled chamber of a valve for controlling pressurization of the water is associated with the water pressurizing region in the housing of the water storage unit, and the input of the controlling chamber of a valve for controlling drainage is associated with the clean water discharge pipe upstream of the tap, wherein the valve for controlling pressurization of the water is normally open and the valve for controlling drainage is normally closed. The claimed water purification system is highly reliable and provides a high quality of purified water.

The present inventions relate to the means for water treatment, preferably drinking water, and can be used in domestic water purification systems.

Known are domestic reverse-osmosis system with a storage device for water that contains placed in the outer housing of the storage tank elastic shell hermetically separating its cavity into two parts: the internal part changing cyclically its volume depending on the amount of purified water in it, and the outer part arranged between the shell and the housing of the storage tank, and also comprises a control valve for water pumping into the outer chamber and control valve for water drain from the cavity to drainage.

In the prior art, there is known a number of U.S. Pat. Nos. 4,579,242; 4,585,554; 4,604,194; 4,629,568; 4,650,586; 4,705,625; 4,776,952; 4,885,085; 4,997,553; 5,662793, etc.) that describe water purification systems with storage devices for water comprising air cavity.

At the same time, in water purification systems, used are mechanical valves (for example, U.S. Pat. No. 4,997,553), piston type valves (for example, U.S. Pat. No. 3,887,463), membrane type valves (for example, U.S. Pat. No. 4,190,537).

However, practical implementation of these devices is difficult since it requires a complex, highly reliable control system for water-to-water storage device.

There is known a water purification system using a device for accumulate pure filtered water, which is described in U.S. Pat. No. 6,764,595 published on 20 Jun. 2004, produced by Kinetico Inc., which is chosen as a prototype for the system and storage device.

The system includes a reverse-osmosis membrane, storage tank and control unit (block diagram shown in FIG. 3). The storage tank of the known water purification system is equipped with an elastic shell arranged inside an external vessel of the tank, which shall is intended for purified water (leachate or permeate), and a pumping area formed in the space between the shell and the vessel housing. In the system of water purification, the input of reverse-osmosis membrane intended to supply pressurized tap water, and the output of reverse-osmosis membrane coupled with the shell cavity of the storage tank is connected with the tap for clean water by means of an outlet pipe.

Another output of reverse-osmosis membrane is connected with the drainage where the water with filtered impurities (concentrate) is discharged. For managing water pumping into the storage tank and discharge the concentrate into the drainage, the system is equipped with two control valves connected in series, one after the other. That is, the system control unit includes a water-pressure-sensitive automatic primary control valve for water pumping (Pilot Valve), which valve has a controlling chamber and a controlled chamber, as well as a slave valve (Servo Valve) for drainage control with a controlling chamber and a controlled chamber. The controlling chamber of the Pilot Valve is connected with a tap of clean water via an outlet pipe, and the input of the controlled chamber is connected with the pipe-line. In the drainage control valve, the input of the controlled chamber is connected to a pumping water zone in the storage tank, and the output of the controlled chamber is connected to the drainage.

The described system uses combined type valves, which valves are driven by control pressure through the chamber containing an elastic membrane, and their shifting is performed by means of a piston spool.

The large number of inputs-outputs for valve of control unit, i.e., large number of points needed in sealing, evidences of high degree of risk of potential leaks in the system, which reduces the reliability of its work. At the same time, a large number of connections in the system, as well as the connecting scheme, in which the control valve for water pumping is not coupled directly to the storage tank, but only through the drainage control valve, allows to make conclusion on the complexity of the water purification system control unit, which reduces reliability of work of the system.

In addition, the storage device has the stagnant zone, which transfers hydraulic pressure, but in which the water is not circulating. In these areas, bacteria and germs develop, penetrate in time in the line of clean water, and deteriorate its quality.

Storage tanks for water treatment systems include flexible membranes (shells, cells) designed to separate objects of storage and accumulate intermediate objects.

There is a group of tank constructions with a membrane that has reduced comparatively with the overall dimensions a connecting part—the neck. Such membrane configuration greatly simplifies connection to the tank housing and organization of stream redirection, allows to reduce sealing part dimensions and therefore tensions in sealing elements. Further, the configuration with the neck provides a possibility to remove the membrane sealing zone from the area of connection of tank housing elements, or at all to use one-piece tank housing.

Using the construction of storage tank with an elastic membrane in the system of water purification is known, for example, from aforesaid U.S. Pat. No. 6,764,595 of Kinetico Incorporated.

Traditionally, similar membranes are manufactured in different methods. One method is direct or transfer (flow) moulding of rubber compounds with subsequent removal of vulcanized products from a punch through a narrowed neck. Some types of rubbers have feature of high relative elongation, and also the punch cross section has figured shape, which allows to carry out the process of removal without damaging the product. The disadvantages of this method are energy intensity and duration of the product vulcanization process, and also the high complexity of the removing operation. Another method for obtaining membranes is pressure molding thermoplastic elastomer with subsequent removing a cooled product from punch through the neck. However, smaller in comparison with rubbers relative elongation of thermoplastic elastomers significantly complicated removing a product and the construction of a punch. Besides, pressure molding technology, which substantially reduces the cycle time, limits the thickness of the casting walls, making it difficult to obtain a membrane with a thickness of baseline minimum to perform its functions.

As a prototype, selected is a storage unit for filtered water described in U.S. Pat. No. 4,997,553 of 5 Mar. 1991, which storage unit includes a housing (of a tank) with an elastic shell inside performed of thermostatic elastomer and fixed to the housing by means of the neck that isolates hermetically the inner cavity intended for storing clean water from the volume formed between housing walls and shell walls intended for discharging process water.

During the operation, the membrane body is cyclically compressed and extended changing divided volumes, while the neck remains firmly fixed in the tank providing a seal. This gives rise to different requirements on mechanical properties of different parts of the membrane: the membrane body shall be more durable, flexible and wear-resistant, while the neck shall be more rigid. The prototype does not solve the aforesaid problem.

The object of the group of claimed inventions is to provide a water purification systems, as well as a device and units used in the system having high reliability and providing high water treatment quality.

The object is achieved at the expense of that the filtered water storage unit for the storage device of the water purification systems comprises a housing with located in it elastic chamber for filtered water, and a pumping zone formed by a space between the chamber walls and housing walls, wherein the elastic chamber is performed of thermoplastic elastomer and consists of a monolithic neck rigidly fixed in the housing and the chamber body, wherein, according to the invention, the said storage unit comprises the chamber body performed of modified thermoplastic elastomer having biaxially oriented structure.

The elastic chamber (membrane) provided in the filtered water storage unit for the storage devices of the water purification system hermetically separates the housing cavity into two parts: the internal part for filtered water and the space between its walls and housing walls for pumping non-treated water thereinto. In the operation, of the elastic body of the chamber-membrane is cyclically compressed and expanded changing volumes separated by it, while the neck remains firmly fixed in the housing. The chamber body material has a biaxially oriented polymer structure obtained in the manufacturing process. The elastic chamber is produced by a two-stage blow forming method. At the first stage of blow forming the thermoplastic elastomer, a small sized work piece is obtained, in which the neck had been formed for future chamber. In the second stage, the neck of the heated work piece is fixed, and the heated work piece is blown with extending to finite size. Thus, in the second stage, the neck material does not change, and the body material has been modified, wherein the temperature and strain rate are determined from the conditions of performing cold orientational crystallization. The aforesaid processes are described in the following sources: 1. G. M. Bartenev, S. Y. Frenkel, “Polymer Physics”, L.: Chemistry, 1990; 2. G. H. Briston, L. L. Katan, “Polymer Films”, M.: Chemistry, 1993; 3. V. E. Gul, V. N. Kuleznev, “Structure And Mechanical Properties Of Polymers”, M.: Publishing House “Labyrinth”, 1994.

Such a modification of the polymer supramolecular structure (hereinafter—SMS) results in reduced brittleness (increased impact strength), increased ductility, increased bending fatigue strength, hence, considerably increased a resistance of the chamber to cyclic loads during operation. The presence of polymer oriented structure also increases the walls barrier properties and, thus, reduces likelihood of diffusion of chemicals through the chamber walls [1], [2], [3].

In particular embodiments, chamber body walls of the storage unit for filtered water are at least 20% thinner than walls of its neck walls; said walls preferably have a thickness between 0.1 to 5 mm, most preferably 0.3 to 2 mm. All figures are obtained experimentally. The body chamber material SMS modification allows to have a smaller body wall thickness as compared with the membrane neck. This provides the body chamber with more flexibility, while the neck being thickened ensures fixture rigidity and a hermetic seal in the housing. The neck great rigidity promotes flow arrangement inside the storage unit for filtered water not allowing a flexible chamber body to close input and output openings. Reducing the chamber body wall thickness also reduces the weight of the product.

In the particular case of implementation, the chamber body walls of the storage unit for filtered water are performed of thermoplastic with biaxially oriented structure preferably selected from the group of thermoplastic polyolefin elastomers or styrene elastomers. Such choice is determined experimentally as the optimum to use the material for said purposes. As a particular material for the chamber, there can be used a thermoplastic elastomer, for example, Dryflex 600 601 (produced by Nolato Elastotechnic).

Therefore, application of the described above construction improves the chamber resistance to cyclic loads during operation, reduces the weight of a product, improves barrier properties of the chamber. This, in turn, leads to higher reliability and higher quality of water purification.

The object of the invention also is achieved due to the fact that, in the 1st embodiment, the storage device of the system for water purification comprises the storage unit for filtered water and a hydroautomatic unit, wherein the storage unit for filtered water is a case with the positioned inside elastic chamber for filtered water, and the pumping zone formed by space between the chamber walls and the housing for non-treated (pipe line) water, and the hydroautomatic unit has a sensitivity to water pressure automatic control valve that control water pressure in the pumping zone in the body of the storage unit for filtered water equipped with a controlling chamber and a controlled chamber, and an automatic control valve for controlling drainage equipped with a controlling chamber and a controlled chamber,

wherein the controlling chamber input of the control valve for water pumping is designed to connect to the pipeline for purified water, the controlled chamber input of this valve is designed to connect to the water supply, the controlled chamber input of the drainage control valve is connected to the water-pumping zone in the housing of the filtered water storage unit, and its output is designed to connect with drainage, wherein, according the invention, the controlled chamber output of the pumping water control valve is connected to the water pumping zone in the housing of the filtered water storage unit, and the controlling chamber input of the drainage control valve is designed to connect to the purified water pipeline, and wherein the water pumping control valve is normally open, and the drainage control valve is normally closed.

In the storage device described in the prototype (U.S. Pat. No. 6,764,595 of Kinetico Incorporated), the hydroautomatic unit operates as follows. When the pure water pipeline pressure increases (when the clean water tap is closed), control (primary) valve (Pilot Valve) comes into the state, in which the slave valve (Servo Valve) is open for connection to the drainage, so water flows, through the said valve, from the pumping zone in the filtered water storage unit housing into the drainage, non-purified water pressure applied to the elastic chamber walls of the storage unit is reduced, and the elastic chamber is filled with pure filtered water. If the clean water tap is open, pressure in the pure water pipeline decreases, the control (primary) valve (Pilot Valve) changes its state so, that the slave valve (Servo Valve) is closed for connection to the drainage and is open for connection to the water supply line, which results in that the pipeline water, via the said valve, enters the storage unit pumping zone, making pressure applied to the elastic chamber walls and press out therefrom a filtered water into the clean water pipeline.

Thus, in the prototype, automatic valves of the hydroautomatic unit are connected to the filtered water storage unit in sequence, i.e., when the purified water pipeline pressure changes, at first the control (primary) valve (Pilot Valve) changes its state, and then, due to series connection of the controlled chamber output of the said valve to the controlling chamber input of the slave valve (Servo Valve), there is changed the status of the said second valve connected to the pumping water zone in the storage unit housing.

In the proposed storage device, according to the 1st embodiment of the present invention, the hydroautomatic unit operates as follows. When the clean water tap is closed (raised pressure in the pure water pipeline), the pumping control valve is closed, and the drainage control valve is open, which results in that untreated water flows from the pumping zone of the storage unite into the drainage via the said valve, the untreated water pressure applied to elastic chamber walls in the storage unit is reduced, and the elastic chamber is filled with pure filtered water. If the pure water tap is open, pressure in the pure water pipeline drops, the pumping control valve opens, and the drainage control valve is closed, resulting in the supply line water flows through the said valve, enters the pumping zone of the storage unit, exerts pressure applied to elastic chamber walls, and push out filtered water therefrom into the clean water line.

Thus, in the proposed storage device, controlling chambers inputs of both automatic valves (the pumping control valve and the drainage control valve) are designed to connect to the purified water pipeline, and the controlled chambers outputs of these valves are connected to the water pumping zone in the housing of the filtered water storage unit. Thus, it may be said that the automatic pumping control valve and automatic drainage control valve are connected in parallel to the water pumping zone in the housing storage unit for filtered water.

At series connection of automatic valves of the hydroautomatic unit with the filtered water storage unit in the storage device of the prototype, there are stagnant, so-called “dead”, zones, which transfer hydraulic pressure, but do not allow water to circulate, namely:

-   -   connection of the purified water pipeline with the controlling         chamber input of the control (primary) valve (Pilot Valve) (the         water pumping and drainage control valves, in the proposed         solution);     -   connection of the controlled chamber input of the of the control         (primary) valve (Pilot Valve) (the water pumping control valve,         in the proposed solution) from the tapping point of this         connection to one of controlled chamber inputs of the slave         valve (Servo Valve) (drainage control valve, in the proposed         solution);     -   connection of one of controlled chamber outputs of the control         (primary) valve (Pilot Valve) (the water pumping control valve,         in the proposed solution) to the is controlling chamber input of         the slave valve (Servo Valve) (drainage control valve, in the         proposed solution)—this connection is absent in the inventive         solution;     -   connection of one of controlled chamber outputs of the control         (primary) valve (Pilot Valve) (the water pumping control valve,         in the proposed solution)—this connection is absent in the         inventive solution.

In these areas, there are developed bacteria and microbes which penetrate with time in the clean water pipeline and deteriorate its quality. In the claimed device performed according to the 1st embodiment, all of the specified zones, except the first, are absent, which results in improving the quality of filtered water.

The proposed storage device circuit allows to use, as automatic valves of the hydroautomatic unit, different design valves in comparison with valves used in the prototype. There are used spool type valves, in which pure filtered water (permeate) and untreated (supplied) water are separated by only a thin membrane, in case violation of which the microbes from supplied water can get into the filtered water. The claimed device uses automatic valves with elastic membrane, in which there is an air cavity (coupled with the atmosphere) between clean water and supplied water, which prevents ingress of microbes into filtered water and in the clean water tap in case of possible damage of the membrane.

In addition, for implementation of the proposed storage device, as an automatic valves of the hydroautomatic unit, there are used valves with one input and one output of the controlled chamber, in comparison with controlled chamber valves with three inputs and three outputs in the prototype, which reduces the number of compounds in the inventive device, simplifies its design and increases the device reliability.

The aforesaid object is achieved also due to the fact that in the 2nd embodiment, the storage device of the water purification system comprises a filtered water unit storage and hydroautomatic unit, wherein the filtered water storage unit is a housing containing inside the elastic chamber for filtered water and a non-treated (supplied) water pumping zone formed by space between chamber walls and the housing, and the hydroautomatic unit has the water pressure sensitive automatic valve for controlling pumping water in the pumping zone in the filtered water storage unit housing with the is controlling and controlled chambers, and a drainage automatic control valve having controlling and controlled chambers,

wherein, according to the invention, the water pumping control valve in the pumping zone in the filtered water storage unit housing and the drainage control valve are combined constructively together and have a single controlling chamber, wherein the controlling chamber input and output are designed for connecting to the pure water pipeline, the controlled chambers of the pumping control valve and the drainage control valve are connected to the controlling chamber in parallel,

wherein the water pumping control valve normally is open, and the drainage control valve normally is closed, and wherein the controlled chamber input of the water pumping control valve is designed to connect to the water supply, and the output is connected to the pumping zone in the filtered water storage unit housing, and the controlled chamber input of the drainage control valve is connected to the pumping zone in the filtered water storage unit housing, and its output is intended for connection with drainage.

In the storage device described in the prototype (U.S. Pat. No. 6,764,595 of Kinetico Incorporated) the hydroautomatic unit operates as described above (1st embodiment).

In the claimed storage device, according to 2nd embodiment, the hydroautomatic unit operates as follows. If the clean water tap is closed, pressure in the clean water line is increased, which causes a reaction of the controlling chamber that is common for both automatic valves, which input and output are designed to connect to the pure water line, wherein the water pumping control valve is set to closed position, and the drainage control valve is set to open position, resulting in that untreated water from the storage unit pumping zone is discarded into the drainage, pressure of unpured water applied to the storage unit elastic chamber walls is reduced, and the elastic chamber is filled with clean filtered water. If the clean water tap is open, clean water pressure in the clean water pipeline drops, the pumping control valve opens, and the drainage control valve closes, resulting in supplied water enters the storage unit pumping zone via the said valve, exerts pressure on the elastic chamber walls and presses out therefrom filtered water into the clean water pipeline.

That is, in the claimed storage device implemented according 2nd embodiment, when the input and output of the controlling chamber being common for both automatic valves (the pumping control valve and the drainage control valve) are designed for connecting to the clean water pipeline, and the controlled chambers outputs of both said valves are connected to the water pumping zone in the filtered water storage unit housing, then the automatic water pumping control valve and the automatic drainage control valve are connected in parallel to the water pumping zone in the filtered water storage unit housing.

Thus, in the storage device performed according to 2nd embodiment, two independent controlling chamber of automatic valves replaced with one, which simplifies the scheme, reduces the number of water connections, and thus reduces the risk of external leakage. At the same time, the cost of manufacturing the device decreases due to reducing the number of places requiring a sealing.

In the case of the storage device implementation according of the 2nd embodiment, as in the 1st embodiment, the controlling chamber is separated from the controlled part by the air cavity connected with the atmosphere, which makes it impossible streaming of water from one cavity into another, thus avoiding, in a case of damage of the membrane, getting untreated water (comprising bacteria and viruses) into purified water for users.

In addition, in the storage device implemented according to the 2nd embodiment, there are no dead zones (places, in which water does not flow), listed in the description of the storage device according to the 1st embodiment, including the zone, which is remained in the device according to the 1st embodiment, namely, the point of connection the pure water pipeline with a common controlling chamber of hydro unit valves (the control (primary) valve (Pilot Valve), in the prototype). That is, in the proposed storage device implemented according the 2nd embodiment, there are absent “dead” zones, which leads to further improving the quality of filtered water.

In particular embodiments of the storage device for the water purification system implemented according to both embodiment 1 and embodiment 2, the filtered water storage unit chamber body walls are performed of thermoplastic with biaxially-oriented structure.

As mentioned above, using, as a chamber body material, a modified polymer with biaxially-oriented structure, obtained in the manufacturing process, result in reduced fragility, increased ductility, increased bending fatigue strength, and, therefore, increased resistance of the chamber to cyclic loads during operation. The presence of oriented structure in the polymer also increases the walls barrier properties and, therefore, reduces a risk of diffusion of chemicals through the chamber walls.

In particular embodiments of the storage device for the water purification system, implemented according to both embodiment 1 and embodiment 2, the filtered water storage unit chamber body walls performed of thermoplastic with biaxially-oriented structure are preferably selected from the group of thermoplastic polyolefin elastomers or thermoplastic styrene elastomers. As mentioned above, the such choice has been determined experimentally as the best material to use for those purposes.

In particular embodiments of the storage device for the water purification system implemented according to both embodiment 1 and embodiment 2, the filtered water storage unit chamber body walls are at least 20% thinner than the walls of its neck; the walls preferably have thickness from 0.1 to 5 mm, most preferably 0.3 to 2 mm. As mentioned above, all numerical values are obtained experimentally and are optimal for this purpose.

Comparative analysis of the storage device implemented according to both embodiment 1 and embodiment 2 in relation of the prototype shows that the proposed technical solution differs from the prototype and achieves the aforesaid object.

The aforesaid object is also achieved at the expense of that, according to the 1st embodiment, the water purification system includes a reverse osmosis membrane, a clean water outlet pipe, a drain for the water with impurities, a clean water tap and the storage device, which includes a storage unit for storing filtered water and a hydro automatic unit;

wherein the filtered water storage unit comprises: a housing having located inside an elastic chamber for filtered water and an untreated (supplied) water pumping zone formed by a space between the chamber walls and the said housing walls; and the hydro automatic unit comprises: a water pressure sensitive automatic control valve for control of water pumping in the pumping zone, which automatic control valve is located in the housing of the filtered water storage unit and has a controlling chamber and a controlled chamber, and a drainage automatic control valve having a controlling chamber and a controlled chamber;

wherein the reverse osmosis membrane input is connected to a pressurized water supply pipeline, the purified water (permeate) output of the reverse osmosis membrane is connected, by the outlet pipe, with the clean water tap and an elastic chamber inside cavity in the filtered water storage unit housing, the reverse osmosis membrane output with water comprising filtered impurities (concentrate) is connected to drainage by a drain pipe, the controlling chamber of the water pumping control valve is connected to the outlet pipe for treated water, the controlled chamber input of the said valve is connected to the water supply, the controlled chamber input of the drainage control valve is connected to the water pumping zone in the filtered water storage unit housing, and its output is connected to the drainage;

according to the invention, the controlled chamber output of the water pumping control valve is connected to the water pumping zone in the filtered water storage unit housing, and the controlling chamber input of the drainage control valve is connected to the clean water outlet pipe upstream of the tap, wherein the water pumping control valve is normally open, and the drainage control valve is normally closed.

The aforesaid object is also achieved at the expense of that, in the 2nd embodiment, the water purification system includes a reverse osmosis membrane, a clean water outlet pipe, a drainage for water with impurities, a clean water tap and a storage device that includes a filtered water storage unit and a hydro automatic unit,

wherein the filtered water storage unit comprises: a housing having located inside an elastic chamber for filtered water and an untreated (supplied) water pumping zone formed by a space between the chamber walls and the said housing walls; and the hydro automatic unit comprises: a water pressure sensitive automatic control valve for control of water pumping in the pumping zone, which automatic control valve is located in the housing of the filtered water storage unit and has a controlling chamber and a controlled chamber, and a drainage automatic control valve having a controlling is chamber and a controlled chamber;

wherein the reverse osmosis membrane input is connected to a pressurized water supply pipeline, the purified water (permeate) output of the reverse osmosis membrane is connected, by the outlet pipe, with the clean water tap and an elastic chamber inside cavity in the filtered water storage unit housing, the reverse osmosis membrane output with water comprising filtered impurities (concentrate) is connected to drainage by a drain pipe,

according to the invention, the water pumping control valve in the pumping zone in the housing of filtered water storage unit and the drainage control valve are constructively combined together and have a single common controlling chamber, wherein the said controlling chamber input and output are connected to the line of pure water outlet pipe upstream of the pure water tap, controlled chambers of the water pumping control valve and the drainage control valve are connected to the controlling chamber in parallel,

wherein the water pumping control valve is normally open, and the drainage control valve is normally closed, at the same time, the controlled chamber input of the water pumping control valve is connected to the water supply, and the controlled chamber output is connected to the pumping zone in the filtered water storage unit housing, the controlled chamber input of the drainage control valve is connected to the pumping zone in the filtered water storage unit housing, and its output is connected to the drainage.

Thus, the proposed water purification system implemented according the 1st and 2nd embodiments is the reverse osmosis system having the storage device including the clean water storage unit and the control unit. At the same time, in the water purification system implemented according to the 1st embodiment, there are used the above-described storage device performed according to the 1st embodiment, and in the water purification system implemented according to the 2nd embodiment, there are used the above-described storage device performed according to the 2nd embodiment.

In this connection, the proposed water purification system implemented according to the 1st and 2nd embodiments, has all of the above-indicated benefits and advantages as compared with the system described in the prior art, which result in simplification of the device, increasing the reliability of its operation and raising quality of filtered water intended for use by consumers.

In particular implementations according to both the 1st and the 2nd embodiments, the water purification system further comprises a prefilter, placed upstream of the reverse osmosis membrane. The prefilter has one or more filters for prepurifying supplied water and remove from it mechanical particles (e.g., sand) and/or chemical compounds (e.g., chlorine), which destroy the membrane. Therefore, the prefilter improves water filtration quality and increases operating life of the RO membrane, i.e., increases the life of the system as a whole.

In particular implementations according to both the 1st and the 2nd embodiments, the water purification system further comprises a shut-off hydraulically operated valve installed upstream of the reverse osmosis membrane and connected to the pure water outlet pipe.

The said valve closes the water flow to the reverse osmosis membrane in the case, if there are no water discharge in the clean water pipeline, and the water storage unit elastic chamber of the storage device is entirely filled with water, because otherwise untreated water passes through the membrane and discharged to the drainage. I.e., the shut-off hydraulically operated valve protects the reverse osmosis membrane from excessive usage in the said cases, increases its service life, increases water filtration quality, increases the water purification systems operation life and water saving.

In particular implementations according to both the 1st and the 2nd embodiments, the water purification system further comprises a check valve, which is installed in the pure water (permeate) pipeline upstream of the hydro unit.

Additional installation of the check valve in the water treatment system protects the hydro unit valves against false triggering, when the pressure drops in the filled chamber of the filtered water storage unit. This, in turn, protects the system against excessive consumption of water poured in the drainage, which increases the service life of the membrane, improves water filtration quality and increases the whole system life.

In particular implementations according to both the 1st and the 2nd embodiments, the water purification system further comprises a postfilter installed in the pure water pipeline (permeate) upstream of the tap.

Additional installation of the postfilter allows to finally prepare a water for use by a consumer (for example, to remove off-odors, make certain minerals water saturation), i.e., improves the system operation quality.

In particular implementations according to both the 1st and the 2nd embodiments, the filtered water storage unit chamber body in the water purification system is performed of modified thermoplastic elastomer with biaxially oriented structure, which, in particular, is preferably selected from the group of thermoplastic polyolefin elastomers or thermoplastic styrene elastomers.

In this case, in particular, the filtered water storage unit chamber body walls are at least 20% thinner than the walls of his neck.

Thus, in particular, the filtered water storage unit chamber body walls preferably have a thickness of 0.1 to 5 mm, most preferably 0.3 to 2 mm.

Since the proposed water purification system implemented according to both the 1st and the 2nd embodiments comprises a reverse osmosis system with a clean water storage device including water storage unit and a control unit, in the said system, in all particular cases of its implementation, there are used the filtered water storage unit described above, embodied in particular different cases as described above, the use of which allows to obtain additional benefits that were specified at describing the filtered water storage unit in general and special cases.

Therefore, the proposed water purification system implemented according to both the 1st and the 2nd embodiments has all of the above-indicated benefits and advantages as compared with the system described in the prior art, which results in improving the quality of filtered water and increasing the reliability of the whole system operation.

The proposed group of inventions entitled as “Filtered water storage unit for a storage device of a water purification system, the storage device of the water purification systems (embodiments), the water purification system (embodiments)” are illustrated by the following drawings.

FIG. 1 shows a functional diagram of the water purification system according to the 1st embodiment with using the storage device according to the 1st embodiment, and the filtered water storage unit:

a) state at closed a clean water tap;

b) state at open clean water tap.

FIG. 2 shows a functional diagram of the water purification system according to the 2nd embodiment with using the storage device according to the 2nd embodiment, and the filtered water storage unit:

a) state at closed clean water tap;

b) state at open clean water tap.

FIG. 3 shows a functional diagram of the water purification system of “Kinetico” company (prototype):

a) state at closed clean water tap;

b) state at open clean water tap.

FIG. 4 shows an example of structural embodiment (1st embodiment):

a) a drainage automatic control valve; and b) a water pumping automatic control valve.

FIG. 5 shows an example of structural embodiment (2nd embodiment) of automatic control valves for water pumping and drainage control with a common controlling chamber.

The proposed water purification system in the general case of implementation performed according to the 1st embodiment with use in it the proposed storage device performed according to the 1st embodiment and also the proposed storage unit for filtered water (FIG. 1) comprises the reverse osmosis membrane 1, the outlet pipe 2 of is the clean water pipeline, a drainage 3, a clean water tap 4 and a storage device 5 comprising a filtered water storage unit 6 and a hydroautomatic unit 7,

wherein the filtered water storage unit 6 has a housing 8 with located inside an elastic chamber 9 for filtered water and a pumping zone 10 for untreated (supplied) water, which zone created by space between the chamber walls and the housing walls, and the hydroautomatic unit 7 comprises a water pressure-sensitive automatic control valve 11 for water pumping control in the housing 8 of the filtered water storage unit 6 with a controlling chamber and controlled chamber, and automatic control valve 12 for drainage control with a controlling chamber and controlled chamber,

wherein the water pumping control valve 11 normally is open, and the drainage control valve 12 is normally closed, the input of the reverse-osmosis membrane 1 is connected to the pressurized water supply, the output of the reverse-osmosis membrane 1 with the purified water (permeate) is connected with the clean water tap 4 via the outlet pipe 2 and with the inner cavity of the elastic chamber 9 in the housing 8 of the filtered water storage unit 6, and the output of the reverse-osmosis membrane 1 with water including filtered impurities (concentrate) is connected to the drainage 3.

At the same time, the controlling chamber of the water pumping control valve 11 is connected to the outlet pipe 2 for purified water, the controlled chamber input of the said valve 11 is connected to the water supply, the controlled chamber input of the drainage control valve 12 is connected to the water pumping zone 10 in the housing 8 of the filtered water storage unit 6, and its output is connected to the drainage 3; the controlled chamber output of the water pumping control valve 11 is connected to the water pumping zone 10 in the housing 8 of the filtered water storage unit 6, and the input of the controlling chamber of the drainage valve control 12 is connected to the pure water outlet pipe 2 upstream of the tap 4.

The proposed water purification system in the general case of implementation according to the 2nd embodiment with use in it the proposed storage device implemented according to the 2nd embodiment, and also the proposed storage unit for filtered water (FIG. 2) comprises the reverse osmosis membrane 1, the outlet pipe 2 of the clean water pipeline, the drainage 3, the clean water tap 4 and the storage device 5 including the filtered water storage unit 6 and hydroautomatic unit 7,

wherein the filtered water storage unit 6 comprises the housing 8 with located inside the elastic chamber 9 for filtered water and the pumping zone 10 for untreated (supplied) water, which zone created by space between the chamber walls and the housing walls, and the hydroautomatic unit 7 comprises the water pressure-sensitive automatic control valve 11 for water pumping control in the housing 8 of the filtered water storage unit 6 with the controlling chamber and the controlled chamber, and the automatic control valve 12 for drainage control with the controlling chamber and the controlled chamber,

wherein the input of the reverse-osmosis membrane 1 is connected to the pressurized water supply, the output of the reverse-osmosis membrane 1 with the purified water (permeate) is connected with the clean water tap 4 via the outlet pipe 2 and with the inner cavity of the elastic chamber 9 in the housing 8 of the filtered water storage unit 6, and the output of the reverse-osmosis membrane 1 with water including filtered impurities (concentrate) is connected to the drainage 3.

At the same time, the water pumping control valve 11 in the pumping zone 10 in the housing 8 of the filtered water storage unit 6 and the drainage control valve 12 are constructively combined together and have the single common controlling chamber, which by its input and output is connected to the outlet pipe 2 (permeate) upstream of the pure water tap 4, controlled chambers of the water pumping control valve 11 and the drainage control valve 12 are connected to the controlling chamber in parallel,

wherein the water pumping control valve 11 normally is open, and the drainage control valve 12 normally is closed, and wherein the input of the controlled chamber of the water pumping control valve 11 is connected to the water supply pipeline, and the output of the controlled chamber of the water pumping control valve 11 is connected to the pumping zone 10 in the housing 8 of the filtered water storage unit 6, the input of the controlled chamber of the drainage control valve 12 is connected to the pumping zone 10 in the housing 8 of the filtered water storage unit 6, and its output is connected to the drainage.

In particular cases of implementing the water purification system according to both the 1st and the 2nd embodiments, the system further comprises the prefilter 13 installed upstream of the reverse osmosis membrane 1.

In particular cases of implementing the water purification system according to both the 1st and the 2nd embodiments, the system further comprises a shut-off hydraulically operated valve 14 placed upstream of the reverse osmosis membrane 1 and connected to the clean water outlet pipe 2.

In particular cases of implementing the water purification system according to both the 1st and the 2nd embodiments, the system further comprises the postfilter 15 installed in the pure water (permeate) line upstream of the tap 4.

In particular cases of implementing the water purification system according to both the 1st and the 2nd embodiments, the system further comprises the check valve 16 installed in the pure water (permeate) line upstream of the hydroautomatic unit 7.

In particular cases of implementing the water purification system according to both the 1st and the 2nd embodiments with using in it the proposed storage device implemented according to both the 1st and the 2nd embodiments, and also the proposed filtered water storage unit (FIGS. 1, 2), when the body of the elastic chamber 9 of the filtered water unit storage 6 is performed of modified thermoplastic elastomer with biaxially-oriented structure, in particular selected preferably from the group of thermoplastic polyolefin elastomers or thermoplastic styrene elastomers, and also in other particular cases, in which walls of the body of the chamber 9 of the filtered water storage unit 6 are at least 20% thinner than the walls of its neck, or preferably have a thickness of 0.1 to 5 mm, most preferably 0.3 to 2 mm, their units and elements are the same as in the general case of their implementation.

The proposed water purification system in the general case of implementation according to the 1st embodiment, with using in it the proposed storage device implemented according to the 1st embodiment, and also the proposed filtered water storage unit (FIG. 1), is operated as follows.

Initially, the system is not connected to the water supply under high pressure-water supply pipeline, i.e., the inlet valve (is not shown in the drawing) is closed; there is no water in the elastic chamber 9 of the filtered water storage unit 6 of the storage device 5, the drainage automatic control valve 12 is “closed” position, the position of the water pumping control valve 11 does not matter, the pure water tap 4 is open.

At the first turn on the system, i.e., at its connecting to the water supply, the inlet valve (not shown) opens. Since the pure water tap 4 is opened, the pressure in the cavity of the elastic chamber 9 of the filtered water storage unit 6 in the storage device 5 a little more than zero (0 bar). And since the pressure drop across the reverse osmosis membrane (ROM) is nearest to zero, the pressure upstream of the ROM is determined by the pressure in the cavity of the elastic chamber 9 and is also slightly different from zero. Since, in this case, the ROM represent a significant hydraulic resistance, water does not pass through the ROM and does not enter the cavity of the elastic chamber 9 of the filtered water storage unit 6 of the storage device 5, and the water from the supply main pipeline enters the controlled chamber of the water pumping control valve 11.

In the cavity of the controlled chamber of the automatic valve 11, water exerts pressure on the elastic membrane, which hermetically separates it from the cavity connected to the atmosphere; the membrane, in turn, exerts pressure of the end of the rod of the automatic valve 11, and since in the control cavity, this time, there is no pressure (the clean water tap 4 is open), then the pressure is not exerted on the end of the rod from the side of the cavity, which results in displacement of the rod, i.e., the water pumping automatic control valve 11 opens and allows water to flow through it into the water pumping zone 10 of the water storage unit 6 of the storage device 5. The supplied water entering into the pumping zone 10 puts pressure on walls of the easily deformable elastic chamber 9, thereby compressing it and pushing out the technical air, which, through an open clean water tap 4 goes into the atmosphere.

This happens as long as the water entering the pumping zone 10 of the water storage unit 6 of the storage device 5 fills the volume available to it in the housing 8.

Once this occurs, the pressure in the pumping zone 10 starts to increase up to a value slightly lower than the pressure in the main water supply pipeline, after which the flow of water in the pumping zone 10 is terminated. As a result, the pressure at the point upstream of the ROM 1 increases almost up to the pressure in the main water supply, and the water flow to the input of the ROM 1. Passing through the ROM1, the water is split into two streams: the first stream is filtered and purified demineralized water (permeate), which from the output of the ROM via the outlet pipe 2 enters to the clean water pipeline, and the second stream is the water containing filtered impurities including salt (concentrate), which goes to the drainage 3. Since at the same time, the supplied water continues to put pressure on the walls of the elastic chamber 9 of the filtered water storage unit 6 of the storage device 5, the purified water can not get into its cavity and, instead, enters the open clean water tap 4 and freely derives from it.

At this moment, the clean water tap 4 is closed, discharge of clean water (permeate) through the tap stops leading to increased pressure in the clean water pipeline within the system. In this case, the stem of the water pumping automatic control valve 11 begins to move in the direction of the controlled cavity as long as will block the water supply out of it, as a result of which, there is terminated water supply from the water mains into the pumping zone 10 of the filtered water storage unit 6 of the storage device 5. Simultaneously, the stem of the drainage automatic control valve 12 begins to move toward the controlled cavity until it stops and opens, resulting in the untreated water from the water pumping zone 10 of the filtered water storage unit 6 is merged into the drainage via the valve 12, the pressure of untreated water on the wall of the elastic chamber 9 in the storage unit 6 is reduced, and the elastic chamber 9 is filled with clean water.

The process continues until the easily deformable elastic chamber 9 take up the whole volume available for it in the housing 8 of the filtered water storage unit 6 of the storage device 5.

After complete filling the elastic chamber 9 with water, the pressure in the pure water pipeline starts to increase, water supply to the input of the ROM is terminated. The pressure at the point upstream of the ROM 1 increases almost to the pressure in the water mains, and water flows to the input of the ROM 1, i.e., the system takes its initial position.

When the clean water tap 4 is opened, pressure drops in the pure water pipeline, the drainage automatic control valve 12 is closed and terminates the flow of unpured water from the water pumping zone 10 of the filtered water storage unit 6 in the storage device 5 to the drainage, and the water pumping automatic control valve 11 is opened, as a result of which supplied water through the valve 11 begins to flow into the pumping zone 10 of the filtered water storage unit 6 in the storage device 5, creating there the pressure applied to walls of the elastic chamber 9 and pressing out therefrom purified water (permeate) into the pure water pipeline, which water flows to the input of the clean water tap 4 and coming out from its spout.

At closing the clean water tap 4, pressure in the clean water line increases forcing the pumping automatic control valve 11 to close, stopping the flow of untreated water into the pumping zone 10 of the filtered water storage unit 6 in the storage device 5, and the drainage automatic control valve 12 is opened resulting in that non-treated water from the pumping zone of the water storage unit is drained off into the drainage through the valve 12, the pressure of supplied water applied to the walls of the elastic chamber 9 in the storage unit 6 is reduced, elastic chamber 9 is filled with pure filtered water.

Thus, in case of purified filtered water is required, the user then opens and closes the valve 4, and processes described above are repeated. From the description of the proposed water purification systems implemented according to the 1st embodiment with use the proposed storage device according to the 1st embodiment, it follows that because of parallel connection of the water pumping automatic control valve 11 and the drainage automatic control valve 12 with the water pumping zone 10 in the houses 8 of the filtered water storage unit 6 in the storage device 5, in the system compared to the prototype, there are no stagnant zones, in which there is no flow of water, except one (points of connection the fresh water pipeline with inputs of controlling chambers of automatic control valves 11 and 12), in which the bacteria and microbes are developed and penetrate over time in the clean water pipeline, and deteriorate its quality. That is, the use of the proposed system with the appropriate storage device provides better filtered water quality.

In addition, to implement the proposed water purification system having the proposed storage device, as the automatic valves 11 and 12 of the hydroautomatic unit 7, there are used automatic valves with elastic membranes, in which, between clean water and supplied water, there is an air cavity coupled with the atmosphere, which cavity prevents the ingress of bacteria in filtered water and in the clean water tap in case of possible damage to the membrane. At the same time, controlled chambers of the automatic valves 11 and 12 each has only one input and one output as compared with three inputs/outputs of the controlled chamber in the prototype valve, which reduces the number of connections in the proposed device and enhances the reliability of its operation.

The proposed water purification system, in the general case of implementation, performed according to the 2nd embodiment, with use in it the proposed storage device performed according to the 2nd embodiment, and also the proposed filtered water storage unit (FIG. 2), operates, in principle, as according to the 1st embodiment, taking into account the following differences.

The water pumping control valve 11 and the drainage control valve 12 have the single common controlling chamber, which inlet and outlet are connected to the pure water pipeline. When the clean water tap 4 is closed, pressure in the clean water pipeline increases, which cause reaction of the single common controlling chamber of both automatic valves, the water pumping control valve 11 is set into closed position, and drainage control valve 12 is set into open position, resulting in untreated supplied water flows from the water pumping zone 10 of the water storage unit 6 via the said valve 12 is discharged into the drainage, the pressure of unpured water applied to walls of the elastic chamber 9 in the storage unit 6 is reduced, the elastic chamber 9 filled with pure filtered water. If the clean water tap 4 is open, the pressure in the pure water pipeline drops, the water pumping control valve 11 is opened, and the drainage control valve 12 is closed, resulting in the supplied mains water via the valve 11 enters the pumping zone 10 of the water storage unit 6, puts pressure on walls of elastic chamber 9 and squeezes out the filtered water into the clean water pipeline.

And so on, depending on the necessity in purified filtered water, the user opens and closes the valve 4, and the above-described processes are repeated.

From the description of the proposed water purification system implemented according to the 2nd embodiment with use the proposed storage device according to the 2nd embodiment, it follows that, in comparison with the 1st embodiment, combining two controlling chambers of both automatic valves (the water pumping control valve 11 and the drainage control valve 12) in a single common chamber simplifies the scheme, reduces water connections, and thus reduces risk of external leakage.

At the same time, as in the 1st embodiment, as the automatic valves 11 and 12 of the hydroautomatic unit 7, there are used automatic valves with elastic membranes, which controlled chambers each has only one input and one output, which reduces the number of connections in the inventive device as compared with the prototype and increases its operation reliability. In this case also, as in the 1st embodiment, the controlling chamber of the automatic valves 11 and 12 of the hydroautomatic unit 7 is separated from the controlled part by the air cavity coupled with the atmosphere, which makes it impossible to flow of water from one cavity to another, thus avoiding, in case of damaged membrane, entering unpured water (containing bacteria and viruses) in purified water for a user.

In addition, in the system implemented according to the 2nd embodiment with the storage device implemented according to the 2nd embodiment, there are completely missing stagnant zones, i.e., places where there is no flow of water, which in operation, leads, as compared with the prototype and the 1st embodiment, to further improve the quality of filtered water.

In particular implementations of the water purification system according to the 1st and the 2nd embodiments, when it additionally comprises the prefilter 13 installed upstream of the reverse osmosis membrane 1, the system operates in the same way, as in the general case of its implementation, with the following differences.

The installed prefilter 13, which comprises one or more prefilters for cleaning supplied mains water, purifies it from mechanically particles (e.g., sand) and/or chemical compounds (e.g., chlorine) that destroys the reverse osmosis membrane, which improves the quality of water filtration and increases the life of the reverse osmotic membrane 1, i.e., increases the life of the system as a whole.

In particular cases of the water purification system according to the 1st and the 2nd embodiments, when it further comprises the hydraulically controlled shut-off valve 14 installed upstream of the reverse osmosis membrane 1 and connected to the clean water outlet pipe 2, the system operates as in the general case of its implementation, with the following differences.

The installed shut-off hydraulically controlled valve 14, in a case if there are no consumption of clean water, and the elastic chamber 9 of the water storage unit 6 of the storage device 5 is completely filled with water, terminates the flow of water from the water mains to the reverse osmosis membrane 1, since otherwise untreated water passes through the membrane 1 and drains off to the drainage, i.e., protects the reverse osmosis membrane from excessive use in these cases, increases its service life, improves the quality of water filtration, increases the life of water purification systems and provides water saving.

In particular cases of implementing the water purification system according to the 1st and the 2nd embodiments, when it comprises the additional postfilter 15 installed in the clean water line upstream of the tap 4, the system operates as in the general case of its implementation, with the following differences.

The postfilter 15 installed allows water to be completely prepared for its use by a consumer (for example, to cut off extraneous odors, to saturate the water with certain minerals, etc.), i.e., improves the quality of operation of the water purification system.

In particular cases of implementing the water purification system according to the 1st and the 2nd embodiments, when it further comprises the check valve 16, which is installed in the clean water line upstream of the hydroautomatic unit 7, the system operates as in the general case of its implementation, with the following differences.

Additional installation of the check valve 16 in the water purification system protects the valves 11 and 12 of the hydroautomatic unit 7 from a false triggering, when the pressure drops in the filled elastic chamber 9 of the filtered water storage unit 6 of the storage device 5, which protects the system from excessive consumption of water drained into the drainage, extends the life of reverse osmosis membrane 1, improves the quality of water filtration and increases the life of the whole system.

In particular cases of implementing the water purification system according to the 1st and the 2nd embodiments, with use in it the proposed storage device implemented according to the 1st and the 2nd embodiments, and also the proposed storage unit for filtered water (FIGS. 1, 2), when the body of the elastic chamber 9 of the filtered water storage unit 6 is performed of a modified thermoplastic having biaxially-oriented structure, preferably, in particular, of the group of thermoplastic polyolefin elastomers or thermoplastic styrene elastomers, and also in other particular cases, when the walls of the elastic chamber 9 body of the filtered water storage unit 6 are at least 20% thinner than the walls of its neck, or preferably have a thickness of 0.1 to 5 mm, most preferably 0.3 to 2 mm, the system operates as in the general case of its implementation, with the following differences.

As specified above, the use of the modified polymer with biaxially-oriented structure as material for the body of the elastic chamber 9, which modified polymer, in particular, is preferably selected from the group of thermoplastic polyolefin elastomers or thermoplastic styrene elastomers, obtained in the manufacturing process, resulting in reduced fragility, increased ductility, increased bending fatigue strength, and consequently improved stability of the elastic chamber 9 of the filtered water storage unit 6 of the storage device 5 to cyclic loads during operation, and also increases barrier properties of the elastic chamber 9, thus reducing the risk of diffusing through them chemicals from unpured water.

The use of the elastic chamber 9 of the filtered water storage unit 6 of the storage device 5, which has specified numerical value of the thickness of walls of its body, which are optimal for these purposes, does not affect the operation of the storage device and the water purification system according to the 1st and the 2nd embodiments.

To implement the group of proposed invention, namely, the filtered water storage unit, the storage device and the water purification system, both as in the general case and in particular embodiments, there can be principally used the known and applicable in the field of water purification materials, elements and units.

For example, as the reverse osmosis membranes 1, there can be used reverse osmosis membrane ULP1812-50 produced by “Vontron”.

The outlet pipe 2 for the clean water line and drainage 3 can be performed, for example, of polyethylene tube ¼″ (6.35 mm) produced by “John Guest”.

As the clean water tap 4, there can be used, for example, the tap F1207A produced by “Dafeng”.

In the filtered water storage unit 6, the housing 8 can be performed, for example, of polypropylene BD31 OMO produced by “Borealis”, and the elastic chamber 9 can be performed of thermoplastic Dryflex 600601 produced by “Nolato Elastotechnic”.

As the prefilter 13, there can be used, for example, the replaceable filtering module R1-02 produced by “Aquaphor”.

As the shut-off hydraulically operated valve 14, there can be used, for example, the shut-off valve H-V1050B-QC produced by “Applied membranes, Inc.”.

As the postfilter 15, there can be used, for example, the replaceable filtering module K1-07 produced by “Aquaphor”.

As the check valve 16, there can be used, for example, the check valve 3/8SCV produced by “John Guest”.

FIG. 4 shows the example of a constructive implementation of the automatic valves of the hydroautomatic unit 7 used in the 1st embodiment of the water purification system with the storage device according to the 1st embodiment:

a) the drainage automatic control valve 12;

b) the water pumping automatic control valve 11.

These valves are designed by “Aquaphor” on the basis of the known membrane type valves (for example, valve H-V1050B-QC produced by “Applied membranes, Inc.”), which basic components are likely performed.

Positions in FIG. 4 is defined as follows:

-   -   17—body;     -   18—cover;     -   19—spring;     -   20—rod;     -   21—ring;     -   22—ring;     -   23—insert;     -   24—bush;     -   25—membrane;     -   26—rod;     -   27—clamp;     -   28—cover;     -   29—rod;     -   30—bush.

FIG. 5 shows the example of constructive implementation of automatic valves of the hydroautomatic unit 7 used in the 2nd embodiment of the water purification system with the storage device according to the 2nd embodiment. These valves (the water pumping control valve 11 and the drainage control valve 12) in the present embodiment are constructively combined and have a single controlling chamber, and developed by

“Aquaphor” also based on the known membrane-type valves (e.g., valve H-V1050B-QC produced by “Applied membranes, Inc.”), which have similar base components.

Positions in the FIG. 5 is defined as follows:

-   -   18—cover;     -   19—spring;     -   20—rod;     -   21—ring;     -   22—ring;     -   23—insert;     -   24—bush;     -   25—membrane;     -   26—rod;     -   27—clamp;     -   28—cover;     -   29—rod;     -   30—bush;     -   31—housing.

Components shown in FIGS. 4, 5 can be performed of engineering plastics by the bulk forming method in thermoplastic injection-molding machines, excepting the following:

-   -   Spring (poz. 19) can be performed of material resistant to         corrosion (e.g., stainless steel) by wire winding;     -   Rings (poz. 21, 22) and membrane (poz. 25) may be performed by         the bulk forming method of silicone rubber or thermoplastic         elastomer.

DESCRIPTION OF DRAWINGS

FIG. 1 a (the tap is closed)

Water supply mains

-   -   2—Permeate     -   3—Concentrate

Drainage

Water flows Water does not flow 11, 12—controlled chamber, controlling chamber

FIG. 1 b (the tap is open)

FIG. 4 a

Controlled chamber

To the atmosphere

Controlling chamber 

1-32. (canceled)
 33. A filter unit for filtering supply water for producing filtered water in a purified water line for dispensing through a tap, which comprises: (a) a housing in which is disposed a flexible bladder for retaining filtered water and a pumping zone formed between said bladder and said housing; and (b) a hydroautomatic unit including a pressure-sensitive, normally open pumping valve having a pumping valve controlled chamber and a pumping valve controlling chamber, and a pressure-sensitive, normally closed drainage valve having a drainage valve controlled chamber and a drainage valve controlling chamber, said normally closed drainage controlled chamber having an input in flow communication with supply water and an output to drainage, said pumping valve controlling chamber and said drainage valve controlling chamber operating independently and each controlling chamber being in communication with said purified water in said purified water line, wherein when said tap is closed, said purified water in said purified water line flows into said bladder and supply water in said pumping zone flows out through said normally open pumping valve controlled zone to drainage, and wherein when said tap is open, said drainage valve pumping chamber closes and said drainage valve controlled chamber opens permitting supply water to flow though said open drainage valve controlled chamber directly into said pumping zone, thus forcing filtered water in said bladder to flow out to said purified water line and out through said open tap.
 34. The filter unit of claim 33, wherein said housing is made from biaxially-oriented thermoplastic elastomer.
 35. The filter unit of claim 33, wherein said biaxially-oriented thermoplastic elastomer is made from a thermoplastic polyolefin elastomer or a thermoplastic styrene elastomer.
 36. The filter unit of claim 33, wherein said bladder has a body and a neck, said neck being connected to said housing.
 37. The filter unit of claim 36, wherein said bladder body is at least 20% thinner than said neck.
 38. The filter unit of claim 37, wherein said bladder body thickness is between about 0.1 and 5 mm.
 39. A filter unit for filtering supply water for producing filtered water in a purified water line for dispensing through a tap, which comprises: (a) a housing in which is disposed a flexible bladder for retaining filtered water and a pumping zone formed between said bladder and said housing; and (b) a hydroautomatic unit including a pressure-sensitive, normally open pumping valve having a pumping valve controlled chamber and a pressure-sensitive, normally closed drainage valve having a drainage valve controlled chamber, said normally closed drainage controlled chamber having an input in flow communication with supply water and an outlet to drainage, said pumping valve controlled chamber and said drainage valve controlled chamber in communication with a single controlling chamber, said controlling chamber being in connection with said purified water in said purified water line, wherein said pumping valve controlled chamber and said drainage valve controlled chamber being connected independently in parallel, wherein said pumping valve controlled chamber having an input in connection with said supply water and having an output in connection with said pumping zone, and wherein said drainage valve controlled chamber having an input in connection with said pumping zone and having an output in connection with drainage.
 40. The filter unit of claim 39, wherein said housing is made from biaxially-oriented thermoplastic elastomer.
 41. The filter unit of claim 39, wherein said biaxially-oriented thermoplastic elastomer is made from a thermoplastic polyolefin elastomer or a thermoplastic styrene elastomer.
 42. The filter unit of claim 39, wherein said bladder has a body and a neck, said neck being connected to said housing.
 43. The filter unit of claim 42, wherein said bladder body is at least 20% thinner than said neck.
 44. The filter unit of claim 43, wherein said bladder body thickness is between about 0.1 and 5 mm.
 45. A filtered water storage unit for a storage device of a water purification system, comprising: (a) a housing; (b) a modified thermoplastic bladder for filtered water and being located inside the housing and being formed from a biaxially-oriented elastomer and integral rigid neck rigidly connected to said housing; and (c) a pumping zone for untreated water formed by a space between the modified thermoplastic bladder and the housing.
 46. The filtered water storage unit of claim 45, wherein said housing is made from biaxially-oriented thermoplastic elastomer.
 47. The filtered water storage unit of claim 45, wherein said biaxially-oriented thermoplastic elastomer is made from a thermoplastic polyolefin elastomer or a thermoplastic styrene elastomer.
 48. The filtered water storage unit of claim 45, wherein said bladder has a body and a neck, said neck being connected to said housing.
 49. The filtered water storage unit of claim 48, wherein said bladder body is at least 20% thinner than said neck.
 50. The filtered water storage unit of claim 49, wherein said bladder body thickness is between about 0.1 and 5 mm.
 51. A method for producing from supply water filtered water in a purified water line for dispensing from a tap, which comprises the steps of: when said tap is closed: (a) passing purified water from said purified water line into a flexible bladder located inside a housing; and (b) withdrawing supply water from a pumping zone formed between said flexible bladder and said housing through an input to controlled zone of a pressure-sensitive open pumping valve, said pumping valve controlled zone having an output to drainage, said pumping valve also having a controlling zone; and when said tap is open: (c) closing said pumping zone controlled zone to stop withdrawal of supply water from said pumping zone; and (d) passing supply water from an output of a controlled zone of an open pressure-sensitive drainage valve into said pumping zone, thus forcing filtered water in said bladder to flow out to said purified water line and out through said open tap, said drainage valve also having zone a drainage valve controlling zone in connection with said purified water in said purified water line, wherein said pumping valve controlling zone and said drainage valve controlling zone operate independently.
 52. The method of claim 51, wherein said housing is made from biaxially-oriented thermoplastic elastomer.
 53. The method of claim 51, wherein said biaxially-oriented thermoplastic elastomer is made from a thermoplastic polyolefin elastomer or a thermoplastic styrene elastomer.
 54. The method of claim 51, wherein said bladder has a body and a neck, said neck being connected to said housing.
 55. The method of claim 54, wherein said bladder body is at least 20% thinner than said neck.
 56. The method of claim 55, wherein said bladder body thickness is between about 0.1 and 5 mm.
 57. A method for producing from supply water filtered water in a purified water line for dispensing from a tap, which comprises the steps of: when said tap is closed: (a) passing purified water from said purified water line into a flexible bladder located inside a housing; and (b) withdrawing supply water from a pumping zone formed between said flexible bladder and said housing through an input to a pumping valve controlled zone of a pressure-sensitive, normally open pumping valve, said pumping valve controlled zone having an output to drainage; and when said tap is open: (c) closing said pumping zone controlled zone to stop withdrawal of supply water from said pumping zone; and (d) passing supply water from an output of a drainage valve controlled zone of an open drainage valve into said pumping zone, thus forcing filtered water in said bladder to flow out to said purified water line and out through said open tap, said pumping valve controlled chamber and said drainage valve controlled chamber in communication with a single controlling chamber, said controlling chamber being in connection with said purified water in said purified water line, wherein said pumping valve controlled chamber and said drainage valve controlled chamber being connected independently in parallel, and wherein said pumping valve controlled chamber having an input in connection with said supply water and having an output in connection with said pumping zone, and wherein said drainage valve controlled chamber having an input in connection with said pumping zone and having an output in connection with drainage.
 58. The method of claim 57, wherein said housing is made from biaxially-oriented thermoplastic elastomer.
 59. The method of claim 57, wherein said biaxially-oriented thermoplastic elastomer is made from a thermoplastic polyolefin elastomer or a thermoplastic styrene elastomer.
 60. The method of claim 57, wherein said bladder has a body and a neck, said neck being connected to said housing.
 61. The method of claim 60, wherein said bladder body is at least 20% thinner than said neck.
 62. The method of claim 61, wherein said bladder body thickness is between about 0.1 and 5 mm. 